Your humble correspondent couldn’t make his second consecutive attendance at the annual Open-Xchange Summit in Cologne, Germany last week, but the web-based messaging and collaboration provider used its event to share some key SaaS and email milestones. Foremost among them: thanks to some key partnerships, Open-Xchange is going to hit 42 million users by the end of the year – that’s a 75 percent boost from 2010.

TalkinCloud has remarked on some of those partnerships in the past. Open-Xchange has largely been focusing its efforts on getting larger web service providers and telcos, especially those in Europe, to switch over to its platform. Providers like STRATO in Germany brought over 5 million seats, while an alliance with Parallels enabled it to nab partnerships with six providers the world over. Altogether, it sounds like adoption is skyrocketing.

Meanwhile, Open-Xchange also demonstrated the next version of its namesake software, which is expected to drop in the last half of 2012. In the press release, the messaging provider claims a focus on “content, speed and simplicity,” going so far as to refer to the redesigned interface as “next generation” Web mail for the “Web age.”

It sounds like it’s going to have the same kind of cross-platform appeal that so many cloud vendors are going for — the current measure of an application’s worthiness is if it looks as good on an Apple iPad as it does on the desktop. That’s a lot of hype and not a lot of specifics. But if it’s really a year out, it’s small wonder Open-Xchange isn’t quite ready to spotlight the new release.

Something I’m disappointed not to hear more about is the Open-Xchange Web Desktop, which was the centerpiece of the 2010 event I attended. That said, in the year since it was announced, it seems just a little less revolutionary: these days, the increasingly popular Google Chrome browser integrates with web apps, and the Google Chromebooks use quite literally a web desktop. This is just a hunch, but I’m wondering if Open-Xchange is planning on gussying it up somehow before they take it back out.

We’ll be keeping an eye on Open-Xchange as it continues its service provider push against Microsoft, so stay tuned.